Explosion pot electric switch



y 1937- I c. C(GARRARD EXPLOSION POT ELECTRIC SWITCH Filed July '7, 1936 Fig.1.

Fig. 2.

//VV/V7'0/? ATTORNEY Patented May 25, 1937 r EJNEITED STATES PATENT OFFIQE EXPLOSION POT ELECTRIC SWITCH Charles Cornfield Garrard, Sutton Coldfield, Birmingham, England, assignor to The Genoral Electric Company Limited, London, England Application July 7, 1936, Serial No. 89,328 In Great Britain July 24, 1935 3 Claims. (Cl. 200-150) This invention relates to explosion pot switches the circles of which the sectors form part. The of the side blast type. With this form of explointermediate plates M which divide the side outsion switch good results are obtained when let vertically are unprovided with nozzle shaped heavy currents are to be interrupted by arrangpassages, but are formed with sector shaped 5 ing that an electrode on which the arc roots Openings l2 which register with the sector upon opening of the switch is near the side outhaped Ope it in the oflternete plates 4 let of the pot so that the arc experiences a strong and which are suitably extended to allow passage transverse blast almost directly after formation of the respect ve movable arcing Contact The thereof. This arrangement, however, does not e t r shap d p n n formalarse p -w y 1o prove So satisfactgyy hen the current to be on the side of the movable arcing contact remote broken is small and the transverse blast weak, from the side outlet. The plates 4 and M are since the arc tends to persist for a relatively long clamped to an inwardly extending peripheral period, and an object of the invention is the proflange l5 which is provided at the lower end of vision of electric switches which will effect rapid th l S el D 2 and Which is faced With interruption whether the current is large or small. insulating material The lower outer Surface of 15 According to the present improvement an exthe said part 2 is also covered with insulating plosion pot switch of the above type is provided material- The lower end 0f the p is Closed y with a plurality of explosion pots in which the a plat 3 f rm d with an p r ur f r the explosion blasts for disrupting and extinguishing Sa o e respective movable arcing Contact the arcs are arranged to occur in succession after Which is of rectangular Cross Section The Said 20 all the arcs have been started at the same time in Contact When in the closed position Substantially the respective pots. In this way there is pro- Closes the l vided a switch or" the character indicated that is Each fiXcd arcing Contact 3 is clamped to a elfective for breaking the circuit whether the boss provided at the inner end of the bell current is large or small. shaped part on the inside thereof. The con- 25 One arrangement in accordance with the inta ts p i a pa f t s I 8 adapt d vention will now be described by way of example to n a t opp t sides of the movable 0011- with reference to the accompanying drawing in act and each Comprising a tip Supported on a which Figure 1 shows diagrammatically an 1 spring finger and forced inwardly by reinforcing 0 vation partly in cross-section of an explosion pot Springs switch of the side blast type embodying t The two explosion pots are connected in series vention and Figures 2 and 3 show plan vi f in one phase and it will be seen that in the leftthe plates of insulating material forming the hand p the fi arcing Contacts are p ed blast chambers of the explosion ot near the upper end of the side outlet 5, whilst In the drawing, each explosion pot l comprises in the right-hand p the fixed a c C ntacts an upper substantially bell shaped part 2 of for are p d at a distance from e ppe en example non-magnetic steel in which the fixed of the Side outletarcing contacts 3 are disposed and to the bottom In Operation When on Opening e Sw tch the of which are clamped a number of plates 4, !4 current is relatively weak and is not interrupted 0 of suitable insulating material constituting an at the fi explosion h the nd p 4 extension of the bell shaped part and forming a e arc in the Second eXloloision l t side outlet divided vertically into a number of r and pot, is drawn to a substantial length passages 5. Thus alternate plates 4 are each before the movable arcing contact of that pot is formed with a nozzle shaped passage 5 leading Withdrawn through the nozzle Shaped p e of from a sector ll shaped opening through the the uppermost 0f t a t r at plat s. H nce 45 plate to the periphery of the plate, The oxwhen such withdrawal opens the side of the explosion pots are carried on bushings 6, I mounted DloSion pot the are experiences a Strong transon the upper n Of the Switch t A t verse blast and is soon extinguished. On the 'cally moving member it carries the moving conother d When on opening the Sw t e Ourtacts 9, lo co-operating with the fixed contacts r nt is r l v ly strong it s p y rrup ed 50 in the two explosion pots. The member 8 is 010- et the first cXlolosion D the d Dotcrated by means, not shown, outside the switch In e arrangement Shown above, Contact ptank. Each movable arcing contact 9 or i 0 is oration in the two pots occurs simultaneously, but adapted to move through the throats of the pasin an alternative arrangement the contacts in sages 5 immediately adjacent to the centres of one pot may be arranged to separate before the 55 contacts in the other pot. Conveniently the lengths of the movable arcing contacts may be adjustable and then by adjusting the length of one of the said contacts, the separations may be caused to occur at different instants of time.

Moreover, it is not essential that the side outlets of the explosion pots should be divided; if desired, the side outlet to each pot may be formed as an undivided aperture in the wall of the pot.

Obviously the arrangement may also be applied to any usual system or arrangement of explosion p ots within the scope of the invention.

I claim:

1. An explosion pot electric switch wherein the explosion blasts of individual pots of a plurality of associated pots occur in succession, comprising at least two associated explosion pots, explosion blast means for the respective pots, an arcing contact mounted within each explosion pot, the blast means and contact of the respective pots being relatively spaced apart different distances in the associated pots so that the explosion blasts will occur in succession and separable arcing contacts for cooperation with the contacts in the respective explosion pots arranged to be simultaneously separated from the corresponding pot contacts and thereafter withdrawn through the explosion blast means of the pots so that arcs established between the cooperating contacts are subjected to the explosion blasts in succession.

2. An explosion pot electric switch wherein the explosion blasts of individual pots of a plurality of associated pots occur in succession, comprising a plurality of associated explosion pots, an explosion blast chamber for each explosion pot, an arcing contact located in each explosion pot and spaced from the corresponding blast chamber, the distance between the respective contacts and chambers being difierent for each of the associated pots and a corresponding plurality of separable arcing contacts arranged for movement through the respective blast chambers and for cooperation with the explosion pot contacts of the several pots, said separable contacts being mounted to be withdrawn from the corresponding explosion pot contacts simultaneously, the arrangement being such that arcs established between the respective contacts of the associated pots are subjected to the explosion blasts in succession.

3. The explosion pot electric switch as in claim 2 wherein the contacts of the several associated explosion pots are so arranged that the circuit =4 breaks are in series.

CHARLES C. GARRARD. 

